Evaluation of secondary dispersal in a large-seeded tree Aesculus turbinata: a test of directed dispersal

Evaluation of secondary dispersal in a large-seeded tree Aesculus turbinata: a test of directed... Among the several hypotheses on selective advantage of seed dispersal, the directed dispersal hypothesis explains the advantage of non-random seed transportation by animals to particular patch type suitable for offspring establishment. We tested this hypothesis in dispersal of a large-seeded, rodent-dispersed tree (Aesculus turbinata) in a temperate forest. We investigated the change in location of seeds through secondary dispersal, and the survival and growth of seedlings at their destinations. Hemispherical photographs taken at the seed locations both before and after secondary dispersal were used to evaluate the consequence of dispersal. Survival and growth rates of seedlings were measured to evaluate the responses of seedlings to light, the most important factor for seedling establishment in A. turbinata. Survival and growth rates of the seedlings were both positively correlated with light conditions, indicating the advantage of dispersal to the microsites with more light available. However, light levels at seed destinations were not significantly different from those at the locations of seeds before secondary dispersal nor those of the surrounding background forest floor. Survival of newly-emerged seedlings varied as a function of light level but not seedling density. This suggests that the effect of density-dependent mortality was small relative to light-dependent mortality during the seedling stage. Therefore we conclude that the directed dispersal hypothesis for this species is rejected, and that the role of rodents in dispersing large seeds secondarily is more important for finding suitable sites merely by enlarging seed shadow (mean dispersal distance = 12.2–44.7 m during the 3 years studied, max. = 41.5–114.5 m) and relatively less important for escaping natural enemies. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Plant Ecology Springer Journals

Evaluation of secondary dispersal in a large-seeded tree Aesculus turbinata: a test of directed dispersal

Loading next page...
 
/lp/springer-journals/evaluation-of-secondary-dispersal-in-a-large-seeded-tree-aesculus-ojCPQeaRBW
Publisher
Springer Journals
Copyright
Copyright © 1999 by Kluwer Academic Publishers
Subject
Life Sciences; Plant Sciences
ISSN
1385-0237
eISSN
1573-5052
DOI
10.1023/A:1009816111057
Publisher site
See Article on Publisher Site

Abstract

Among the several hypotheses on selective advantage of seed dispersal, the directed dispersal hypothesis explains the advantage of non-random seed transportation by animals to particular patch type suitable for offspring establishment. We tested this hypothesis in dispersal of a large-seeded, rodent-dispersed tree (Aesculus turbinata) in a temperate forest. We investigated the change in location of seeds through secondary dispersal, and the survival and growth of seedlings at their destinations. Hemispherical photographs taken at the seed locations both before and after secondary dispersal were used to evaluate the consequence of dispersal. Survival and growth rates of seedlings were measured to evaluate the responses of seedlings to light, the most important factor for seedling establishment in A. turbinata. Survival and growth rates of the seedlings were both positively correlated with light conditions, indicating the advantage of dispersal to the microsites with more light available. However, light levels at seed destinations were not significantly different from those at the locations of seeds before secondary dispersal nor those of the surrounding background forest floor. Survival of newly-emerged seedlings varied as a function of light level but not seedling density. This suggests that the effect of density-dependent mortality was small relative to light-dependent mortality during the seedling stage. Therefore we conclude that the directed dispersal hypothesis for this species is rejected, and that the role of rodents in dispersing large seeds secondarily is more important for finding suitable sites merely by enlarging seed shadow (mean dispersal distance = 12.2–44.7 m during the 3 years studied, max. = 41.5–114.5 m) and relatively less important for escaping natural enemies.

Journal

Plant EcologySpringer Journals

Published: Oct 19, 2004

References

You’re reading a free preview. Subscribe to read the entire article.


DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Search

Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly

Organize

Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.

Access

Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

DeepDyve

Freelancer

DeepDyve

Pro

Price

FREE

$49/month
$360/year

Save searches from
Google Scholar,
PubMed

Create folders to
organize your research

Export folders, citations

Read DeepDyve articles

Abstract access only

Unlimited access to over
18 million full-text articles

Print

20 pages / month

PDF Discount

20% off